1. Field of the Invention
The present invention relates to a mirror angle adjustment mechanism for adjusting a mirror surface angle of a mirror for visually observing rearward of a vehicle.
2. Description of the Related Art
For example, as shown in FIG. 7, a mirror angle adjustment mechanism 100 features a case pivot 102, with a first hemisphere portion 104 having a substantially hemisphere surface formed in the case pivot 102. A substantially cylindrical pivot shaft 106 is formed upright in the central portion of the first hemisphere portion 104 with a self-tapping screw 110 screwed on the tip end of the pivot shaft 106 via a snap ring 108.
A mirror holder inner 112 is disposed in the vehicle rearward side of the case pivot 102 mounted to the vehicle, with a second hemisphere portion 114 having a substantially hemisphere surface formed in the mirror holder inner 112. A circular opening 116 is formed on the case pivot 102 side of the second hemisphere portion 114. The second hemisphere portion 114 is fitted in the first hemisphere portion 104 with the pivot shaft 106 being inserted through the opening 116. Moreover, a mirror for visually observing rearward of the vehicle (not shown) is mounted on the mirror holder inner 112.
In the second hemisphere portion 114, a support pivot 118 is disposed. In the support pivot 118, a cylindrical pivot cylinder 120 is provided, and the pivot cylinder 120 is fitted on the pivot shaft 106. A third hemisphere portion 122 having a substantially hemisphere surface is provided around the pivot cylinder 120, and the third hemisphere portion 122 is fitted in the second hemisphere portion 114.
A compression coil spring 124 is mounted between the third hemisphere portion 122 and the snap ring 108. Thus, a pressuring force is applied to the third hemisphere portion 122 such that the second hemisphere portion 114 is held between the first hemisphere portion 104 and the third hemisphere portion 122.
Therefore, with the mirror angle adjustment mechanism 100, when a tilting force is applied manually to the mirror, the second hemisphere portion 114 is slid with respect to the first hemisphere portion 104 and the third hemisphere portion 122, and the mirror holder inner 112 is tilted so as to adjust the mirror surface angle of the mirror. However, since a friction force is present between the second hemisphere portion 114 and the first hemisphere portion 104 and the third hemisphere portion 122, resisting force can be obtained against tilting of the mirror holder inner 112, so that undesired movements of the mirror can be prevented.
However, according to the mirror angle adjustment mechanism 100, even in a case of providing the snap ring 108 and the self-tapping screw 110 as a single component, at least five parts, that is, the case pivot 102, the self-tapping screw 110, the mirror holder inner 112, the support pivot 118 and the compression coil spring 124 are needed. Therefore, problems are involved in that the number of the parts is large and ease-of-assembly is poor.
Moreover, the pressuring force of the compression coil spring 124 urges only on a central portion of the third hemisphere portion 122, and the pressuring force is not efficiently applied to portions away from the central portion of the second hemisphere portion 114. Furthermore, since the second hemisphere portion 114 and the third hemisphere portion 122 are both formed in a substantially hemisphere form, they can easily be point-contacted due to a slight formation error such as a dent, so that the friction force therebetween may not be obtained sufficiently. Therefore, a problem is involved in that inconvenient (that is, undesired) tilting of the mirror cannot be prohibited since the resisting force against tilting of the mirror holder inner 112 cannot be obtained sufficiently unless the pressuring force of the compression coil spring 124 is large.
In consideration of the above-mentioned facts, an object of the present invention is to provide a mirror angle adjustment mechanism capable of reducing the number of parts and improving of ease-of-assembly.
According to one aspect of the present invention, there is provided a mirror angle adjustment mechanism comprising: a case member including a first hemisphere portion in which a substantially hemispherical surface is formed; a mirror mounting member including a second hemisphere portion, on which a substantially hemispherical surface is formed which slidably fits into the first hemisphere portion and in which an opening is formed; and a lock member for holding the second hemisphere portion of the mirror mounting member between the lock member and the first hemisphere portion of the case member, the lock member including: at least one latching member inserted through the opening of the mirror mounting member and engaging with the case member when the lock member holds the second hemisphere portion of the mirror mounting member between the lock member and the first hemisphere portion of the case member; and a plurality of resilient plates which are deflected when the at least one latching member and the case member are engaged, and press the second hemisphere portion of the mirror mounting member against the first hemisphere portion of the case member.
In the mirror angle adjustment mechanism of the present invention, the latching member of the lock member is inserted through the opening provided in the second hemisphere portion of the mounting member and engaged with the case member. The plurality of elastic plates of the lock member are in a compressed state and urge against the second hemisphere portion such that the second hemisphere portion is held between the plurality of elastic plates and the first hemisphere portion of the case member. By pressuring different portions of the second hemisphere portion with the plurality of elastic plates, the entirety of the second hemisphere portion can be urged.
Therefore, when a tilting force is applied to the mirror mounted on the mounting member by a hand, or the like, the second hemisphere portion is slid against the first hemisphere portion and the plurality of elastic plates such that the mounting member is tilted so as to adjust the mirror surface angle of the mirror. However, since friction force is generated between the second hemisphere portion and both the first hemisphere portion and the plurality of elastic plates, a resisting force can be obtained against tilt of the mounting member. Thus, undesired tilting of the mirror can be inhibited.
Moreover, the mirror angle adjustment mechanism can be assembled with the case member by inserting the latching member of the lock member through the opening of the mounting member, with the second hemisphere portion of the mounting member being superimposed with the first hemisphere portion, so as to engage the latch member with the case member.
Accordingly, since the mirror angle adjustment mechanism has only three members, the case member, the mounting member and the lock member, the number of parts can be reduced and ease-of-assembly can be improved.
Furthermore, the elastic force of the plurality of elastic plates is applied directly on portions away from the central portion of the second hemisphere portion. Moreover, since the plurality of elastic plates is contacted with the second hemisphere portion, they tend to be surface-contacted. Therefore, a resisting force against tilt of the mounting member can be obtained efficiently, and thereby, inadvertent tilting of the mirror can be reliably inhibited.
According to the mirror angle adjustment mechanism of the present invention, the latching member may have rigidity. A load may be applied on the engaging portion of the latching member and the case member at a time of detaching the mirror from the mounting member or the like. By providing the latching member with rigidity, breakage of the latching member can be prevented.
Moreover, according to the mirror angle adjustment mechanism of the present invention, the latching member may include a projecting portion, and the case member may include an engaging hole portion formed to correspond to the latching member for engaging with the latching member. Furthermore, the case member includes, at the engaging hole portion, an engaging portion engaging with the projecting portion of the latching member, for engaging the latching member with the case member, and a non-engaging portion adjacent to the engaging portion and arranged such that the projecting portion of the latching member is insertable into the engaging hole portion at the non-engaging portion without engaging with the non-engaging portion.
According to this configuration, when the latching member is disposed opposing the engaging portion provided for the engaging hole of the case member (provided facing thereto), the projecting portion of the latching member is engaged with the engaging portion such that the latching member is in the state of being engaged with the case member. In contrast, when the latching member is disposed opposing the non-engaging portion provided in the engaging hole adjacent to the engaging portion, the projecting portion of the latching member is not engaged with the non-engaging portion and the latching member is not engaged with the case member.
Therefore, by disposing the latching member opposing the engaging portion by disposing the latching member opposing the non-engaging portion and then relatively moving the lock member with respect to the case member, the latching member can be engaged with the case member without deflecting the latching member. Thus, even if the latching member does not have elasticity, the latching member can be engaged with the case member without breakage of the latching member.
In the above-mentioned aspect of the present invention, the case member may comprise a resilient pawl-form portion at the engaging hole portion, the pawl-form portion being deflectable for allowing relative movement of the latching member from the non-engaging portion side to the engaging portion side after the latching member has been inserted into the engaging hole portion, and being engageable with the latching member for obstructing relative movement of the latching member from the engaging portion side to the non-engaging portion side.
According to this configuration, since the movement of the latching member from the non-engaging portion to the engaging portion can be enabled by the deflection of the elastic nail provided in the engaging hole, the latching member can be engaged with the case member without deflecting the latching member. On the other hand, since the movement of the latching member from the engaging portion to the non-engaging portion can be inhibited by the elastic nail obstructing the latching member, movement of the latching member from the engaging portion to the non-engaging portion by vibrations or the like can be inhibited. Thus, inadvertent release of the engagement of the latching member with the case member can be prevented.